In the past few years, the Web has greatly facilitated the dissemination and sharing of GIS capabilities, leading to the new term Web GIS. This reflects the growing use of the Web as a platform that supports authoring geoprocessing models and maps, then publishing them as services that can be easily consumed by a variety of client applications. Ad hoc consumption of multiple data sources and distributed services makes it easier to find and use geographic information, as well as share it with other GIS professionals, customers, constituents, and the public.

Users can add their own GIS layers to Virtual Earth basemaps.

As an emerging dominant platform for both social and business-driven interaction, Web GIS merges (or mashes up) authoritative content with user-generated content to deliver location-based information and applications to a broader audience. Consumers can view a map showing the locations of gas stations with the lowest prices or analyze the impact a wildfire might have on their home and property. Emergency response officials can use that same wildfire map and add their own data on top of it to analyze how to plan and respond to a worst-case scenario, including routing personnel and equipment and devising evacuation routes for the populations at risk. Local governments can now provide information to their constituents in a more timely and cost-effective manner via the Web, allowing them, for example, to browse homeownership information or parcel records online or inform residents about upcoming street maintenance projects that will impact neighborhood traffic. Common to all these examples is the need for ready-to-use, current, and accurate basemap data that sometimes has to be available on short notice and onto which proprietary data can be easily overlaid, or mashed up, in order to provide information in a useful and meaningful context.

ArcGIS Online Services, powered by ArcGIS Server, can be crawled, indexed, searched, and used to share information and provide analytic capabilities to a broader audience over the Web or a network in the most effective manner. Developers who want to serve live, dynamic mapping applications over the Web can easily implement ArcGIS Online. For example, a viewer application, such as the one featured in the ArcGIS Online Services Resource Center (http://help.arcgis.com/en/arcgisonline/content/index.html#//011q0000001z000000.htm) can be built quickly using the ArcGIS APIs for JavaScript. Users can also add additional content, such as photos or video and sound files.

Besides the tools and content to create and share geographic information, ArcGIS Online Services also provide a common template for geographic information that is forming national and global spatial data services via a federation of ArcGIS systems. These systems, based on a framework of useful cartographic standards and metadata, will enable the sharing and discovery of spatial data and enhance its use by GIS professionals, as well as the public.

To this end, Esri has released ArcGIS Online Services to give users immediate access to consistent content, such as imagery, street maps, topographic maps, shaded relief and land-cover imagery, and other basemaps. Users can leverage standard and premium ArcGIS Online Services content for geocoding, routing, and analysis and to provide the background display for their GIS projects across different geographies. ArcGIS Online standard services are generally available at no cost to ArcGIS users for internal or external noncommercial use. Accessing ArcGIS Online premium services does require purchasing an annual subscription, regardless of internal or external use, but users can evaluate premium services for 14 days before subscribing. ArcGIS Online premium services include USA Prime Imagery, a world imagery service with 1-meter or better seamless imagery for the United States, and Virtual Earth Maps, which presents global high-resolution imagery and detailed global road maps for 67 countries. ArcGIS Online standard services include satellite imagery for the world at 15-meter or better resolution, with 1�2-meter or better resolution for the United States; a multiscale, worldwide street map at 1:100,000 scale for the world and 1:5,000 scale for most urban areas; and a Natural Earth physical map at global and continental scales. ArcGIS Online Services also offer transportation and elevation data, as well as world boundaries and place-names overlays.

The ArcGIS Online Services Resource Center helps users get started and provides a wealth of information about the individual data services, including a directory of services, metadata for each service, and how to use ArcGIS Online Services. It also features a content showcase, which is an Esri-hosted map application built using the ArcGIS API for JavaScript, that lets users preview and browse imagery, streets, topography, and Virtual Earth data.

For those organizations that wish to work with ArcGIS Online content locally or host and publish their own services, Esri provides two additional delivery mechanisms. First, the ArcGIS Data Appliance provides much of the same data available through ArcGIS Online Services, delivered on a preconfigured network storage device. The 2D map and 3D globe data collections are prerendered and precached and are optimized for publishing with ArcGIS Server. This gives organizations the ability to fuse the data with other content and provides a shared GIS platform to internal and external customers for visualization and analysis projects. Second, DataDoors for ArcGIS is an application powered by i-cubed's DataDoors, through which users can order most of the source imagery, topographic maps, and elevation data available through ArcGIS Online Services for use locally with their own data and GIS software. Users can order the data in the coordinate system and file format of their choice and, depending on the size of the data, have it delivered via download locally to their desktop or via FTP, Firewire, CD, or DVD.

Organizations that have high-resolution imagery and want to make it broadly available to their customers or constituents can do so through the ArcGIS Online Content Sharing program. Through this program, user organizations and geographic data providers can contribute their data to ArcGIS Online and give all ArcGIS users free access via the Web. As accepted, Esri will host the user organization's imagery data and provide continuous access via the Web 24 hours a day, 7 days a week. Organizations benefit because it minimizes the need for disk space and hardware requirements and eliminates packaging and distribution logistics associated with disseminating data products to users and customers.

More Information

For more information about ArcGIS Online Services, the ArcGIS Online Services Resource Center, ArcGIS Data Appliance, DataDoors for ArcGIS, and the Content Sharing program, visit www.esri.com/arcgisonlineservices.